Chemical feeder



April 29, 1958 R. E. FARISON CHEMICAL FEEDER 4 Sheets-Sheet l Filod Oct. '7. 1956 w; zmflwiw ATTOEME 5.

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April 29, 1958 R. E. FARISON cmauxcn. FEEDER Filed Oct. '7. 1955 April 29, 1958 son 2,832,366

CHEMICAL FEEDER Filed Oct. 7, 1955 4 Sheets-Sheet S 1b I h MIM ENT R.

April 29, 1953 R. E. FARISON 2,832,366

CHEMICAL FEEDER 4 Sheets-Sheet 4 Filed Oct. 7, 1955 mlmzw United States Patent CHEMICAL FEEDER Robert E. Farison, Cincinnati, Ohio, assignor to The Du Bois Co., Inc., Cincinnati, Ohio, a corporation of California Application October 7, 1955, Serial No. 539,094 8 Claims. (Cl. 13710l.11)

The present invention relates to chemical feeding apparatus and is particularly directed to a novel device for injecting a liquid chemical into a continuously flowing stream.

The principal object of the present invention is to provide a device for injecting a liquid additive into a high pressure stream of liquid without the use of a pump or other high pressure injecting mechanism. A chemical feeder embodying the principles of this invention is susceptible of many uses, but will be described particularly in conjunction with a dishwashing machine.

A large dishwashing machine of the type presently in use in restaurant establishments includes a dish cleaning and rinsing chamber through which the dishes are carried on a wire tray mounted on a suitable conveyer. At the washing station the dishes are subjected to a cleaning spray comprising water and a soluble cleaning compound. At a subsequent station the dishes are rinsed by contact with a spray which preferably contains a wetting agent. The present chemical feeding apparatus is particularly adapted for feeding a liquid wetting agent into the stream of rinse water as it flows towards the rinse sprays.

The present injecting device is effective to introduce measured quantities of wetting agent into the rinse stream at regular, closely spaced intervals of time so that a substantially constant concentration of wetting agent is maintained in the rinse water stream. The operating cycle of the feeder, which is of relatively short duration, for example six seconds, is divided into two parts: a charge accumulating portion and a discharge portion. During the charge accumulating portion of the cycle a predetermined quantity of wetting agent is siphoned from a container and stored in an accumulating chamber; while during the discharge portion of the cycle an auxiliary stream which is diverted from the main rinse stream, picks up the accumulated wetting agent and carries it back into the main rinse stream.

A preferred embodiment of a fluid injecting machine constructed in accordance with the present invention includes a Pitot insert adapted to be placed in the rinse water line to withdraw a portion of the rinse stream and direct it through an auxiliary fluid circuit where it picks up a quantity of wetting agent before reentering the rinse water line through a second Pitot insert. The auxiliary fluid circuit comprises two fluid conduits, a bypass fluid conduit and a primary fluid conduit, the rinse water alternately being directed through one or the other of these conduits. During the discharge portion of the cycle, the auxiliary stream passes through the primary conduit, washes out a charge of wetting agent which has previously been deposited in an accumulating chamber provided in that conduit, and carries the wetting agent back to the main rinse stream. During the charging portion of the cycle the auxiliary stream passes through the by-pass conduit of the feeding device, while a siphon is established in a portion of the primary conduit effective to draw a predetermined quantity of wetting agent from a container into the accumulating chamber provided in that conduit. The fluid flow through the two conduits of the feeding device is controlled entirely by the means of two solenoid operated valves, energized in timed sequence by any suitable form of electric timer.

One of the principal advantages of the present chemical feeder is that although a reagent, such as a wetting agent, is introduced into a relatively high pressure fluid stream, no pump or other high pressure mechanism is employed, rather, the present device employs only simple check valves and two solenoid valves, so that only a minimum amount of maintenance is required even during periods of protracted use.

A further advantage of the present device is that the amount of reagent added to the rinse stream is accurately controlled, and can readily be changed while the device is in operation. In the preferred embodiment of the invention control of the amount of reagent fed to the rinse water stream is provided by a ball type metering valve inserted in the primary fluid conduit. During the discharge portion of the cycle fluid flows in one direction through the metering valve and during the re agent charging portion of the cycle, fluid passes through the metering valve in the opposite direction. The metering valve contains an elongated bore having fluid openings at each end. A ball, or other element of slightly smaller diameter than the bore, is mounted in the bore and is adapted for sliding movement along the bore.

Fluid flowing through the bore passes around the ball, but carries the ball with it from one end of the bore to the other depending upon the direction of fluid flow. A seat is provided at the end of the bore through which fluid enters during the discharge portion of the cycle. A movable abutment member, such as an elongated rod, is fitted in the opposite end of the bore and is elfective to limit the longitudinal travel of the ball when it is carried forward by the fluid stream. During the reagent charging portion of the cycle, the direction of flow within the metering valve reverses and the ball travels from the abutment member toward the seat; when the ball engages the seat it is effective to seal off the siphon line stopping the siphoning action withdrawing reagent from its container. Consequently the amount of reagent siphoned from the container and drawn into the accumulating chamber in the primary fluid conduit is limited by the volumetric displacement of the ball in its travel toward the conical seat. By shifting the rod or other abutment member, the displacement of the ball and the amount of reagent withdrawn during each cycle of the device can readily be varied.

Another advantage of the present invention is that the feeding device is relatively compact since no bulky pump or other pressure mechanism is required. In the pre ferred embodiment the valves and other parts of the feeder are mounted in a housing surrounding the wetting agent container and the entire unit is not substantially larger than the container itself. Consequently, the feeding device can be mounted on a dishwasher without impairing access to any of the other parts of the machine.

These and other objects and advantages of the present invention will be more readily apparent from a further consideration of the following detailed description of the drawings illustrating a preferred embodiment of the invention.

In the drawings:

Figure 1 is a perspective view of a chemical feeder having a portion of the cover broken away to show details of the fluid connections.

Figure 2 is a semi-diagrammatic perspective view, showing various elements of the feeder, partially in section.

Figure 3 is a perspective view of the feeder housing showing various external fluid connections and control switches.

Figure 4 is a bottom view of the feeder unit showing details of the valve energizing circuit.

Figure 5 is a diagrammatic view showing fluid flow during the charge accumulating portion of the cycle.

Figure 6 is a diagrammatic view showing fluid flow during the discharge portion of the cycle.

Figure 7 is a schematic circuit diagram of the valve energizing circuit.

As best shown in Figures 1, 3, and 4, a chemical feeder l0 constructed in accordance with the present invention comprises a housing 11 divided into an upper compartment 12 and a lower compartment 13. The upper compartment is adapted to enclose a reagent container 14 and various elements of the auxiliary fluid circuit 15; while the lower compartment houses solenoid operated valves .16 and 17 and the electrical control circuit for governing the energization of these valves.

More particularly housing 11 includes a rear wall 18, and side walls 20, formed of sheet metal or other suitable material, and door 21, which in the present embodiment is formed of a transparent plastic material such as Lucite and is hinged to one of the side walls as at 22. Any suitable form of latch means 23 are provided for holding the door in the closed position. The housing is also provided with a divider shelf 24 for separating compartments 12 and 13, a ventilating openingZS, and brackets 26 for mounting the housing in any suitable manner upon a dish- 'washer, or the like. Three fluid connections are provided to the housing namely fluid inlet line 27, fluid outlet line 28 and siphon tube 30.

The details of the auxiliary fluid circuit can best be understood from a consideration of Figure 2. As there shown feeding device is connected to the rinse line 31 of a dishwasher. Hot rinse water flows in a continuous stream through rinse line 31 to suitable manifolds (not shown) from which it is directed through sprays onto dishes passing through the washing machine. -In this embodiment the chemical feeder functions to supply predetermined quantities of a wetting agent to the rinse water stream to facilitate the rinsing action. The present chemical feeder may of course be employed in conjunction with other equipment to introduce liquid chemicals into other types of fluid lines if desired.

The chemical feeding device includes auxiliary fluid circuit this circuit is connected to the rinse line at two points by means of Pitot inserts 32 and 33. Pitot insert 32 is connected to inlet line 27 through manual cut off valve 29 and includes an opening 34 directed upstream of the rinse line so that a portion of the rinse stream enters opening 34 of the Pitot tube and is thereby diverted to line 27. The other Pitot insert includes an opening 35 which faces in the downstream direction in the fluid rinse line so that fluid can be discharged through the opening from the feeding unit into the rinse line. This Pitot insert is connected to discharge line 28 through manual cutoff valve 36.

The operation of the chemical feeder is controlled by solenoid actuated valves 16 and 17. As explained in detail below, the solenoid coils 37 and 38 of these valves are energized through a control circuit 40 in such a man ner that the valves are alternately opened and closed and always are maintained in an opposite condition relative to one another. That is, when valve 16 is open valve 17 is closed and vice-versa. Valve 16 controls flow through the primary fluid circuit 41 while valve 17 controls the fluid flow through discharge siphon line 30.

Primary fluid conduit 41 includes tube 42 which is joined to the outlet side of valve 16 and interconnects that valve and a metering valve 43. A short nipple 39 connects valve 43 to trap valve 44. From the trap valve the primary fluid circuit extends through pipe 45, and mixing chamber 46. This cham er is is t rn nected to discharge tube 28.

'In addition to primary fluid circuit 41 a parallel fluid path is provided by by-pass circuit 47, including a throttling valve 48 which communicates with line 27 before solenoid operated valve 16. Throttling valve 48 is joined to line 49 which is in turn connected to mixing chamber 46. Flow through the by-pass circuit is controlled by throttling valve 48 which is fitted with a conical seat 50. A ball 51 is mounted within the valve and a weight 52 is disposed above the ball for urging it toward the seat against the pressure of the entering fluid.

When valve 16 is closed, all of the fluid entering the chemical feeder flows through by-pass circuit 47 and is returned through mixing chamber 46 and conduit 28 to the rinse line. While the rinse liquid is flowing through this by-pass path a charge of reagent is drawn into accumulating chamber 53 of trap valve 44. When valve 16 is open, valve 17 is closed so that fluid entering the feeder divides; a portion of the fluid continues to flow through by-pass circuit 47 while approximately an equal amount of fluid passes through valve 16 and enters conduit 42. It will be understood that the exact ratio of fluid division between these two circuits is not critical and will vary with many factors such as the pressure of the rinse line and the like. The fluid entering conduit 42 passes through metering valve 43 and trap valve 44, washing out the charge of reagent that has-accumulated in chamber 53 and carrying that charge to mixing chamber 46. From the mixing chamber the admixed auxiliary stream and reagent pass through conduit 28 into the rinse stream flowing in pipe 31.

During the charging portion of the cycle reagent from 1 container 14 is drawn into accumulating chamber 53, through line 54 which is connected to the lower end of trap valve 44 and to a tube 55 mounted within the reagent container 14. Tube 55 has an inlet opening disposed adjacent to the bottom of container 14 and is provided with a pop-up flow indicator ball 56, this ball being raised from its seat when reagent is withdrawn from the container. Line 54 is joined to trap valve 44 at the lower end thereof and communicates with accumulating chamber 53 through a bore 57 adapted to be closed by a ball check valve 58.

As explained above, accumulating chamber 53 is also connected to metering valve 43 through nipple 39. Metering valve 43 includes a central bore 59 having a ball 60 formed of nylon or other material mounted therein. The diameter of the ball is only slightly smaller than bore 59, so that the ball has a slight clearance, ,4, of an inch for example. Consequently, the ball moves up and down within the bore in accordance with the direction of fluid flow therein. Means are provided for adjustably limiting the travel of ball 60 within the chamber. In the embodiment shown these means comprise rod 62 which extends into the bore through compression fitting 63 and a suitable gasket such as 0 rings 64. The rod is adapted for sliding movement up and down, whereby its end 65 can be selectively positioned within chamber 59.

The position of this rod within the chamber determines the displacement of ball 60 during the charging portion of the cycle and thereby regulates the amount of reagent introduced into the rinse stream in each cycle. A suitable plate 66, provided with suitable indicia for indicating the amount of fluid to be introduced is mounted on an inner side wall of the housing adjacent to an over turned end 67 of rod 62 to facilitate the correct positioning of the rod to secure a given reagent concentration in the rinse line.

During the charging portion of the cycle valve 16 is closed and valve 17 is open. A siphon leg is formed from the discharge end of tube 30 through valve 17,'conduit 42, metering valve 43, trap valve 44, and tube 54 to the reagent container 14. Consequently reagent is withdrawn from this container upwardly through conduit 54 into accumulating chamber 53 of the trap valve. However, as liquid siphons through chamber 53 and is withdrawn through bore 59 of valve 43, nylon ball 60 which had previously been forced into contact with rod 62, moves downwardly toward conical seat 68. When the nylon ball engages this seat the siphoning action is automatically stopped. Consequently, the amount of reagent drawn governed through control circuit 40. The elements of this circuit are best shown in Figures 4 and 7. As there shown, an alternating current motor 71, such as a synchronous motor, is energized from alternating current power lines 72 and 73. This motor drives a star shaped cam 74, through a suitable gear drive the details of which are not shown, so that the cam is rotated at a constant rate of speed. A conventional on and off switch 75 is inserted in power line 72 and a pilot lamp 76 is connected across the power lines to provide a visual indication when the power circuit is closed.

Power line 73 is connected to one end of valve solenoid coils 37 and 38, while the other end of these coils is returned to line 72, through a single pole, double throw switch 77. This switch is actuated by a follower 78 tracking on cam 74. The cam and follower are arranged so that switch 77 closes the circuit to solenoid coil 37 for four seconds and then closes the circuit to solenoid coil 38 for two seconds; after which it again completes the circuit to solenoid coil 37. Thus during each cycle of operation solenoid coil 37 is energized to open valve 16 for four seconds, valve 17 being closed; and then solenoid coil 38 is energized opening valve 17 for two seconds while valve 16 is closed.

A priming switch 80 is placed in parallel electrical connection with switch 77 between line 72 and solenoid 38. By closing this switch, solenoid 38 can be energized continuously to hold valve 17 open, permitting fluid to flow through valves 16 and 17 out through discharge siphon 30. This provides a simple means of rapidly priming that siphon when the device is first put into use.

The operation of the feeding device can best be understood from a consideration of Figures 5 and 6, diagrammatically showing the flow during the reagent accumulating and discharge portions of the operating cycle. In most installations, thereagent feeding device is preferably mounted adjacent to the top of a dishwashing machine with the Pitot inlet and outlet connections 32 and 33 disposed above the level of liquid in reagent container 14. While this arrangement is desirable it is not absolutely necessary so long as a siphon breaking valve 81 is provided in communication with line 45 or at some other point in the primary flow circuit 41. Siphon tube 30 is disposed with its open end below the level of waste liquid and disposed beneath the inlet opening in tube 55.

When the device is ready for operation, switch 75 is closed to start motor 71, actuating switch 77 and energizing valves 16 and 17. Simultaneously priming switch 80 is closed to hold valve 17 open. This permits fluid to flow directly through inlet conduit 27, valves 16 and 17 and siphon tube 30 to prime that siphon tube in a minimum amount of time. After siphon tube 30 has been filled with liquid, priming switch 80 is opened, so that the energization of solenoid coil 17 is again controlled by switch 77.

When switch 77 reaches the position diagrammatically shown in Figure 7, so that coil 37 is energized and valve 16 is open, fluid enters conduit 27, passes through valve 16 and passes upwardly through conduit 42, valve 17 being closed to prevent passage of fluid through siphon tube 30. The fluid thus enters the primary flow path and enters metering valve 43 where it passes upwardly through bore 59, carrying nylon ball 60 upwardly until it engages end 65 of rod 62. The fluid is discharged from metering valve 43 into accumulating chamber 53 of trap valve 44 where the fluid picks up a charge of reagent previously drawn into that chamber. Any downward flow of fluid into the reagent bottle is blocked by check valve 58. However, fluid is permitted to flow upwardly past check valve 82 into conduit 45, through mixing chamber 46, discharge conduit 28 and Pitot insert 33 into the rinse stream flowing in pipe 31.

The flow continues through this primary flow path throughout the entire discharge portion. of the cycle lasting approximately four seconds. At the end of that time switch 77 is actuated by the rotation of cam 74 so that the circuit is broken to solenoid coil 37 and solenoid coil 38 is energized, closing valve 16 and opening valve 17. When valve 16 closes fluid is forced into bypass line 47 through throttling valve 48. The fluid flows from conduit 49 through the mixing chamber, conduit 28 and Pitot tube 33, back into the rinse line.

The opening of valve 17 establishes a siphon leg through tube 30, valve 17, conduit 42, metering valve 43, trap valve 44 and conduit 54 to reagent container 14. Consequently, as shown in Figure 5, as liquid drains downwardly through tube 30 reagent is forced upwardly through conduit 54 into accumulating chamber 53. Meanwhile, the downward flow of liquid through bore 59 carries nylon ball 60 downwardly until that ball engages seat 68. When this occurs conduit 42 is sealed oil? and the siphoning action stops. Thus the amount of reagent drawn upwardly into chamber 53 is equal to the volume of fluid displaced by the movement of nylon ball 60 from its position in engagement with rod 62 to its position in contact with seat 68. During this charge accumulating portion of the cycle, fluid flowing in the bypass circuit is prevented from entering chamber 53 by the action of check valve 82.

When the position of switch 77 is again reversed at the start of the discharge portion of the cycle, valve 17 is closed and valve 16 is opened to admit fluid to the primary fluid conduit 41 so that the fluid washes the reagent from chamber 53 and carries it into the rinse line as explained above.

While the length of cycle time is not critical a relatively rapid cycling rate of the order of a few seconds is advantageous since a substantially constant ratio of reagent to rinse water is maintained.

As indicated above in the event that Pitot connections 33 and 34 must be made below the level of liquid in container 14 siphon breaker 81 is provided to prevent a siphon path being established from the reagent container directly to the discharge line. This siphon breaker in cludes a ball'83 adapted to be forced against a suitable seating element 84 such as an O ring disposed above the ball; so that the ball is pressed into sealing engagement with the ring whenever fluid pressure is present in chamber 85 of valve 44. However, when no fluid pressure is present in this line ball 83 drops to provide an air inlet into the space thereby preventing a siphoning action from taking place.

From the foregoing discussion of the general principles of this invention and from the above description of a preferred embodiment those skilled in the art will readily comprehend the various modifications to which the invention is susceptible. It will also be appreciated that while the chemical feeder of the present invention is particularly suited for introducing reagents into a continuously moving stream such as the hot water rinse stream of a dishwasher, it can also be employed in conjunction with fluid lines having an intermittent flow.

. Having described my invention I claim:

1. A chemical feeder adapted to inject an additive into a flowing stream, said feeder comprising an inlet line and an outlet line communicating with said stream, a siphon line, a bypass conduit interconnecting said inlet line and said outlet line, a primary conduit interconnecting said inlet line and said outlet line, a first solenoid actuated valve effective to close ofl said primary conduit whereby fluid flows through said bypass conduit, a second solenoid actuated valve adapted to simultaneously connect said primary conduit to said siphon line, whereby fluid in said primary'conduit is drained through said siphon line, an accumulating chamber disposed in said primary conduit, an additive container, a fluid line interconnecting said container and said accumulating chamber, whereby when fluid drains through said siphon line additive is drawn into said accumulating chamber, and means for alternately energizing said solenoid valves, whereby their conditions are reversed, the second valve closing off said siphon line, and the first valve opening said primary conduit to fluid flow, so that fluid from said stream flows through said inlet line and primary conduit, mixes with additive in said accumulating chamber and discharges said additive from the outlet line.

2. A chemical feeder adapted to inject an additive into a flowing stream, said feeder comprising an inlet line and an outlet line communicating with said stream, a siphon line, a bypass conduit interconnecting said inlet line and said outlet line, a primary conduit interconnecting said inlet line and said outlet line, a first solenoid actuated valve effective to close off said primary conduit whereby fluid flows through said bypass conduit, a second solenoid actuated valve adapted to simultaneously connect said primary conduit to said siphon line, whereby fluid in said primary conduit is drained through said siphon line, an accumulating chamber disposed in said primary conduit, an additive container, 2. fluid line interconnecting said container and said accumulating chamber, whereby when fluid drains through said siphon line additive is drawn into said accumulating chamber, means for alternately energizing said solenoid valves, whereby their conditions are reversed, the second valve closing otf said siphon line, and the first valve opening said primary conduit to fluid flow, so that fluid from said stream flows through said inlet line and primary conduit, mixes with additive in said accumulating chamber and discharges said additive from the outlet line, and a metering valve effective to limit the amount of additive drawn into said chamber.

3. A chemical feeder adapted to inject a liquid reagent intao a liquid stream, said feeder comprising an inlet line, and a discharge line, in communication with said stream a siphon tube, a primary fluid conduit interconnecting the inlet line and the discharge line, said primary fluid conduit being provided with an accumulating chamber, a bypass conduit interconnecting the inlet line and the discharge line, a first solenoid actuated valve adapted to close the primary fluid conduit whereby fluid flows through the bypass conduit, a second solenoid actuated valve adapted to interconnect the primary fluid conduit and the siphon line, cam operated switch means for successively energizing said valves in alternation, a reagent container, a conduit interconnecting said container and said accumulating chamber, so that when the primary conduit is connected to the siphon line reagent is drawn into said accumulating chamber said switch means being effective to reverse the conditions of said valves so that the second valve closes off the siphon line and the first valve opens said primary fluid conduit to fluid flow so that fluid from said stream flows through the inlet line and primary conduit, mixes with the reagent in said accumulating chamber and discharges said reagent from the outlet line.

4. A chemical feeder adapted to inject an additive into a flowing stream, said feeder comprising an inlet line and an outlet line communicating with said fluid stream, a siphon line, a bypass conduit interconnecting said inlet line and said outlet line, a primary conduit interconnecting said inlet line and said outlet line, a first solenoid actuated valve placed in said inlet line intermediate said bypass conduit and primary conduit and being effective to close off said primary conduit whereby fluid flows through said bypass conduit, a second solenoid actuated is closed, whereby said primary conduit is drained through said siphon line when fluid flows through said bypass conduit, an accumulating chamber disposed in said primary conduit, an additive container, a fluid line interconnecting said container and said charge accumulating chamber, whereby when fluid drains through said siphon line additive is drawn into said accumulating chamber, and means for alternately energizing said solenoid valves, whereby their conditions are reversed, the second valve closing off said siphon line, and the first valve opening 'said primary conduit to fluid flow, so that fluid from said stream flows through said inlet line and primary conduit,

mixes with additive in said accumulating chamber and discharges said additive from the outlet line.

5. A chemical feeder adapted to inject an additive into a flowing stream, said feeder comprising an inlet line and an outlet line communicating with said stream, a siphon line, a bypass conduit interconnecting said inlet line and said outlet line, a primary conduit interconnecting said inlet line and said outlet line, a first solenoid actuated valve effective to close 01? said primary conduit whereby fluid flows through said bypass conduit, a second solenoid actuated valve adapted to simultaneously connect said primary conduit to said siphon line, whereby fluid in said primary conduit is drained through said siphon line, and the direction of fluid flow in a portion of said primary conduit is thereby reversed, an accumulating chamber disposed in said primary conduit, an additive container, a fluid line interconnecting said container and said accumulating chamber, whereby when fluid drains through said siphon line additive is drawn into said accumulating chamber, means for alternately energizing said solenoid valves, whereby their conditions are reversed, the second valve closing off said siphon line, and the first valve opening said primary conduit to fluid flow, so that fluid from said stream flows through said inlet line and primary conduit, mixes with additive in said accumulating chamber and discharges said additive from the outlet line, and a metering valve effective to limit the amount of additive drawn into said chamber, said metering valve being connected to the portion of said primary conduit in which the direction of fluid flow is reversed and including an elongated fluid bore, a ball disposed within said bore and having a diameter slightly less than said bore, and a valve seat in one end of said bore adapted to cooperate with said ball to stop the flow of fluid through said metering valve.

6. A chemical feeder adapted to inject an additive into a flowing stream, said feeder comprising an inlet line and an outlet line communicating with said stream, a siphon line, a bypass conduit interconnecting said inlet -line and said outlet line, a primary conduit interconnecting said inlet line and said outlet line, a first solenoid actuated valve effective to close off said primary conduit whereby fluid flows through said bypass conduit, a second solenoid actuated valve adapted to simultaneously connect said primary conduit to said siphon line, whereby fluid in said primary conduit is drained through said siphon line, and the direction of fluid flow in a portion of said primary conduit is thereby reversed, an accumulating chamber disposed in said primary conduit, an additive container, at fluid line interconnecting said container and said accumulating chamber, whereby when fluid drains through said siphon line additive is drawn into said accumulating chamber, means for alternatively energizing said solenoid valves, whereby their conditions are reversed, the second valve closing off said syphon line, and the first valve opening said primary conduit to fluid flow, so that fluid from said stream flows through said inlet line and primary conduit, mixes with additive in said accumulating chamber and discharges said additive from the outlet line and a metering valve effective to limit the amount of additive drawn into said chamber, said metering valve being connected to the portion of said primary conduit in which the direction of fluid flow is reversed and including an elongated fluid bore, a ball disposed within said bore and having a diameter slightly less than said bore, and a valve seat in one end of said bore adapted to cooperate with said ball to stop the flow of fluid through said metering valve, an abutment member in the opposite end of said bore adapted to limit movement of said ball within the bore, and means for adjustably positioning said abutment member.

7. A cyclically operable chemical feeder adapted to inject a liquid reagent into a liquid stream, said feeder comprising an inlet line and a discharge line in communication with said stream, a siphon line, a primary fluid conduit interconnecting the inlet line and the discharge line, a bypass conduit interconnecting the inlet line and the discharge line, means for passing fluid through said primary conduit during a portion of the operating cycle, means for causing a siphon flow through said primary conduit in a reverse direction during another portion of the operating cycle, a reagent container, a line interconnecting said reagent container and said primary conduit, whereby when fluid is siphoned from said primary conduit in a reverse direction, reagent is withdrawn from the reagent container into the primary fluid conduit and when fluid subsequently flows from said inlet line through said primary conduit, the fluid mixes with the reagent and discharges it from said discharge I line.

munication with said stream, a. siphon line, a primary 35 fluid conduit interconnecting the inlet line and the dis charge line, a bypass conduit interconnecting the inlet line and the discharge line, means for passing fluid through said primary conduit during a portion of the operating cycle, means for causing a siphon flow through said primary conduit in a reverse direction during another portion of the operating cycle, a reagent container, a line interconnecting said reagent container and said primary conduit, whereby when fluid is siphoned from said primary conduit in a reverse direction, reagent is withdrawn from the reagent container into the primary fluid conduit and when fluid subsequently flows from said inlet line through said primary conduit, the fluid mixes with the reagent and discharges it from said discharge line, and a metering valve for regulating the amount of reagent drawn into said primary fluid conduit, said metering valve being connected to the portion of said pn'mary conduit in which the direction of fluid flow is reversed and including an elongated fluid bore, a ball disposed within said bore and having a diameter slightly less than said bore, and a valve seat in one end of said here adapted to cooperate with said ball to stop the flow of fluid through said metering valve, an abutment member in the opposite end of said bore adapted to limit movement of said ball within the bore, and means for adjustably positioning said abutment member.

References Cited in the file of this patent UNITED STATES PATENTS 549,479 Hall Nov. 5, 1895 1,943,039 Randolph Ian. 9, 1936 2,058,309 Haering Oct. 20, 1936 2,350,045 Kathe May 30, 1944 

